HD wallet(Hierarchical Deterministic Wallet) has the capability of deriving multiple private keys from one single seed, thus making it easy to do wallet backup or upgrade to other compatible wallets such as hardware wallet.

The seed is represented by a number of words that is easy to remember or write on paper, called mnemonic phrase. In protocol BIP39 a mnemonic phrase is defined in 12 or 24 words.

Based on BIP32, BIP44 allows wallet to store multiple tokens and accounts with one seed.

Since Vite adopts ED25519 for signature, other than secp256k1 used in BIP32, we need to find a key derivation method which is compatible with BIP32. The actual signature implementation in Vite is similar to ed25519-bip32.